libnet/d/bridge: configure store when opts missing

If the GenericData option is missing from the map, the bridge driver
would skip configuration. At first glance this seems fine: the driver
defaults are to not configure anything. But it also skips over
initializing the persistent storage, which is configured through other
option keys in the map. Fix this oversight by removing the early return.

Signed-off-by: Cory Snider <csnider@mirantis.com>

libnetwork/drivers/bridge/bridge.go

@@ -142,7 +142,7 @@ type bridgeNetwork struct {
 }
 
 type driver struct {
-	config            *configuration
+	config            configuration
 	natChain          *iptables.ChainInfo
 	filterChain       *iptables.ChainInfo
 	isolationChain1   *iptables.ChainInfo
@@ -160,7 +160,7 @@ type driver struct {
 
 // New constructs a new bridge driver
 func newDriver() *driver {
-	return &driver{networks: map[string]*bridgeNetwork{}, config: &configuration{}}
+	return &driver{networks: map[string]*bridgeNetwork{}}
 }
 
 // Init registers a new instance of bridge driver
@@ -348,7 +348,7 @@ func (n *bridgeNetwork) isolateNetwork(enable bool) error {
 
 func (d *driver) configure(option map[string]interface{}) error {
 	var (
-		config            *configuration
+		config            configuration
 		err               error
 		natChain          *iptables.ChainInfo
 		filterChain       *iptables.ChainInfo
@@ -360,20 +360,17 @@ func (d *driver) configure(option map[string]interface{}) error {
 		isolationChain2V6 *iptables.ChainInfo
 	)
 
-	genericData, ok := option[netlabel.GenericData]
-	if !ok || genericData == nil {
-		return nil
-	}
-
-	switch opt := genericData.(type) {
+	switch opt := option[netlabel.GenericData].(type) {
 	case options.Generic:
 		opaqueConfig, err := options.GenerateFromModel(opt, &configuration{})
 		if err != nil {
 			return err
 		}
-		config = opaqueConfig.(*configuration)
+		config = *opaqueConfig.(*configuration)
 	case *configuration:
-		config = opt
+		config = *opt
+	case nil:
+		// No GenericData option set. Use defaults.
 	default:
 		return &ErrInvalidDriverConfig{}
 	}

libnetwork/drivers/bridge/bridge_test.go

@@ -1013,7 +1013,7 @@ func TestCleanupIptableRules(t *testing.T) {
 	ipVersions := []iptables.IPVersion{iptables.IPv4, iptables.IPv6}
 
 	for _, version := range ipVersions {
-		if _, _, _, _, err := setupIPChains(&configuration{EnableIPTables: true}, version); err != nil {
+		if _, _, _, _, err := setupIPChains(configuration{EnableIPTables: true}, version); err != nil {
 			t.Fatalf("Error setting up ip chains for %s: %v", version, err)
 		}
 

libnetwork/drivers/bridge/setup_ip_tables.go

@@ -29,7 +29,7 @@ const (
 	IsolationChain2 = "DOCKER-ISOLATION-STAGE-2"
 )
 
-func setupIPChains(config *configuration, version iptables.IPVersion) (*iptables.ChainInfo, *iptables.ChainInfo, *iptables.ChainInfo, *iptables.ChainInfo, error) {
+func setupIPChains(config configuration, version iptables.IPVersion) (*iptables.ChainInfo, *iptables.ChainInfo, *iptables.ChainInfo, *iptables.ChainInfo, error) {
 	// Sanity check.
 	if !config.EnableIPTables {
 		return nil, nil, nil, nil, errors.New("cannot create new chains, EnableIPTable is disabled")

libnetwork/drivers/bridge/setup_ip_tables_test.go

@@ -56,7 +56,7 @@ func TestSetupIPChains(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	driverconfig := &configuration{
+	driverconfig := configuration{
 		EnableIPTables: true,
 	}
 	d := &driver{